Using default OSX apache httpd to serve ~/Sites/foo at http://foo.local
By configuring dns and using virtual hosts - you can automatically serve folders in your ~/Sites directory under a local domain.
Wildcard DNS is a better option that editing your /etc/hosts file for every site, there are a few ways to do this.
http://mikeferrier.com/2011/04/04/setting-up-wildcard-dns-on-localhost-domains-on-osx/